Fire resistant, high flow poly(aryl ether sulfone) composition

ABSTRACT

Polymer composition (C) containing (i) a poly(aryl ether sulfone) material (M12) composed of a poly(biphenyl ether sulfone) (P1) and, optionally in addition, a poly(aryl ether sulfone) (P2) containing recurring units with arylene groups linked to each other via a secondary, ternary or quaternary carbon atom, and (ii) a per(halo)fluoropolymer material (M34), composed of a per(halo)fluoropolymer (P3) of which at least 2.0 wt. % of the recurring units are derived from a per(halo)fluoromonomer other than tetrafluoroethylene, and a polytetrafluoroethylene (P4). 
     Shaped article, especially aircraft interior component, comprising the polymer composition (C).

CROSS-REFERENCE TO A RELATED APPLICATION

The present application is a Continuation application of U.S. Ser. No.12/990,805, filed Nov. 3, 2010; which is a U.S. National Stageapplication under 35 U.S.C. §371 of International Application No.PCT/EP2009/055513, filed May 7, 2009, which claims the benefit of U.S.application Ser. No. 61/051,746, filed May 9, 2008, the whole content ofwhich is herein incorporated by reference for all purposes.

The present invention relates to a new high flow polymer compositioncomprising a poly(aryl ether sulfone) material and a fluoropolymermaterial. The new polymer composition exhibits an outstanding balance ofproperties and is especially well suited for the manufacturing ofaircraft interior components.

The terms “high flow” are commonly used by the skilled person to qualifya polymer composition that has a low melt viscosity at high shear rates(typically well above 1000 s⁻¹, up to 10,000 s⁻¹); high flow materialsmake it possible to mold thin-walled, and consequently light-weight,aircraft interior components.

For several years, the industry, in particular the aircraft industry,has required fire resistant and robust materials for the manufacturingof aircraft interior components such as wall panels, overhead storagelockers, serving trays, seat backs, cabin partitions, and ducts.

Among engineering polymers, poly(biphenyl ether sulfone)s, especiallypolyphenylsulfones, offer as such a rather attractive combination ofproperties, especially high stiffness, high toughness, and also a ratherhigh fire resistance and a rather high flowability. For these reasons,they appear to be engineering polymers of premium choice for use as thebase ingredient of a polymer composition for the manufacturing ofaircraft interior components. Yet, neat poly(biphenyl ether sulfone)sare generally not suitable for the manufacturing of aircraft interiorcomponents: materials having both a higher fire resistance and a higherflowability than neat poly(biphenyl ether sulfone)s are generallyrequired by the aircraft industry.

It has already been attempted to increase the fire resistance ofpoly(biphenyl ether sulfone)s. For example, U.S. Pat. No. 5,204,400 andSer. No. 5,916,958 exemplify various polymer compositions comprising apoly(biphenyl ether sulfone), a polytetrafluoroethylene, and anhydrouszinc borate and/or titanium dioxide; the compositions of US '400 and US'958 are in general still not suitable for the manufacturing of aircraftinterior components because none of the above listed additives(polytetrafluoroethylene, and anhydrous zinc borate and/or titaniumdioxide) helps to reduce substantially the melt viscosity.

US 2007/0037928 describes the use of a fluorocarbon polymer comprisingrecurring units derived from a perfluorinated mono-olefin and aperfluoroalkylvinylether (such as MFA) for lowering the melt viscosityof poly(biphenyl ether sulfone)s and other sulfone polymers, so thatpoly(biphenyl ether sulfone) compositions exhibiting a flowability ashigh as desirable by the aircraft industry can be produced. The choiceof MFA or the like makes it further possible to provide poly(biphenylether sulfone) compositions exhibiting a fire resistance as high asdesirable (as otherwise obtainable e.g. by the incorporation ofpolytetrafluoroethylene). In a particular embodiment of US 2007/0037928,as shown in example 5, the poly(biphenyl ether sulfone) composition mayfurther include a bisphenol A polysulfone, which can also help to reducethe melt viscosity. The compositions of US 2007/0037928, while realizinga substantial progress when compared to the previously availablepoly(biphenyl ether sulfone) compositions, are still not as performingas desirable for the manufacturing of aircraft interior componentsbecause the use of MFA or the like results in a substantial loss oftoughness, as measured in terms of maximum load and total energyabsorbed to maximum load by the penetration impact DYNATUP® test.

The present invention addresses this problem, by providing a new polymercomposition which exhibits surprisingly a unique combination of highfire resistance, high flowability (as high as desirable to make itpossible to mold thin-walled, and consequently light-weight, aircraftinterior components), high stiffness and high toughness, especially asmeasured by the DYNATUP® test.

Then, a first aspect of the present invention concerns a polymercomposition (C) containing

-   -   between 50 and 100 wt. %, based on the total weight of the        polymer composition (C), of a poly(aryl ether sulfone) material        (M12), composed of        -   from 55 to 100 wt. %, based on the total weight of the            poly(aryl ether sulfone) material (M12), of at least one            poly(biphenyl ether sulfone) (P1), and        -   from 45 to 0 wt. %, based on the total weight of the            poly(aryl ether sulfone) material (M12), of at least one            poly(aryl ether sulfone) (P2) of which more than 50 wt. % of            the recurring units are recurring units (R2) containing at            least one ether group (—O—), at least one sulfone group            (—SO₂—) and at least two arylene groups linked to each other            via a secondary, ternary or quaternary carbon atom, and    -   between 0 and 25 wt. %, based on the total weight of the polymer        composition (C), of a per(halo)fluoropolymer material (M34),        composed of        -   from 5 to 95 wt. %, based on the total weight of the            per(halo)fluoropolymer material (M34), of at least one            per(halo)fluoropolymer (P3) of which at least 2.0 wt. % of            the recurring units are recurring units (R3) derived from at            least one per(halo)fluoromonomer other than            tetrafluoroethylene, and        -   from 95 to 5 wt. %, based on the total weight of the            per(halo)fluoropolymer material (M34), of at least one            polytetrafluoroethylene (P4).

The Poly(Aryl Ether Sulfone) Material (M12)

As previously mentioned, the polymer composition (C) contains apoly(aryl ether sulfone) material (M12).

For the purpose of the invention, a poly(aryl ether sulfone) material isintended to denote one or more poly(aryl ether sulfone)s, i.e. one ormore polycondensation polymers of which more than 50 wt. % of therecurring units contain at least one ether group (—O—), at least onesulfone group (—SO₂—) and at least one arylene group.

The poly(aryl ether sulfone) material (M12) is contained in the polymercomposition (C) in an amount of preferably more than 75 wt. %, and morepreferably more than 90 wt. %, based on the total weight of polymercomposition (C). On the other hand, the weight of the poly(aryl ethersulfone) material (M12), based on the total weight of polymercomposition (C), is preferably below 98%, more preferably below 96% andstill more preferably below 94%.

The poly(biphenyl ether sulfone) (P1) is contained in the poly(arylether sulfone) material (M12) in an amount of from 55 to 100 wt. %,based on the total weight of the poly(aryl ether sulfone) material(M12). The weight of the poly(biphenyl ether sulfone) (P1), based on thetotal weight of the poly(aryl ether sulfone) material (M12) [i.e. theweight of the poly(biphenyl ether sulfone) (P1) plus the weight ofpoly(aryl ether sulfone) (P2)], is preferably of at least 65% and morepreferably at least 75%. The weight of the poly(biphenyl ether sulfone)(P1), based on the total weight of the poly(aryl ether sulfone) material(M12), may be of at least 85% or at least 90%.

Especially when extremely high toughness is desirable, the weight of thepoly(biphenyl ether sulfone) (P1), based on the total weight of thepoly(aryl ether sulfone) material (M12), is preferably of at least 95%or of at least 99%; good results were obtained when the poly(aryl ethersulfone) material (M12) consisted essentially of (or even, consisted of)the poly(biphenyl ether sulfone) (P1).

On the other hand, when extremely high flowability is desirable, theweight of the poly(biphenyl ether sulfone) (P 1), based on the totalweight of the poly(aryl ether sulfone) material (M12), is preferablybelow 95%; otherwise said, in such a case, the weight of the poly(arylether sulfone) (P2), based on the total weight of the poly(aryl ethersulfone) material (M12), is preferably above 5%; it is more preferablyabove 10% and still more preferably above 15%.

The Poly(Biphenyl Ether Sulfone) (P1)

The poly(aryl ether sulfone) material (M12) contains at least onepoly(biphenyl ether sulfone) (P1).

For the purpose of the invention, a poly(biphenyl ether sulfone) isintended to denote a polycondensation polymer of which more than 50 wt.% of the recurring units are recurring units (R1) contain at least oneether group (—O—), at least one sulfone group (—SO₂—) and at least onep-biphenylene group:

Preferably, recurring units (R1) comply with the general structuralformula:

wherein R₁ through R₄ are —O—, —SO₂—, —S—, —CO—, with the proviso thatat least one of R₁ through R₄ is —SO₂— and at least one of R₁ through R₄is —O—; Ar₁, Ar₂ and Ar₃ are arylene groups containing 6 to 24 carbonatoms, and are preferably phenylene or p-biphenylene; and a and b areeither 0 or 1.

More preferably, recurring units (R1) are selected from the groupconsisting of:

and mixtures thereof.

Still more preferably, recurring units (R1) are

Optionally, the poly(biphenyl ether sulfone) (P1) further comprisesrecurring units (R1*) other than recurring units (R1).

Recurring units (R1*) may be selected from the group consisting of:

and mixtures thereof.

The poly(biphenyl ether sulfone) (P1) may notably be a homopolymer, arandom, alternating or block copolymer.

Preferably more than 70 wt. % and more preferably more than 90 wt. % ofthe recurring units of the poly(biphenyl ether sulfone) (P1) arerecurring units (R1). Still more preferably, essentially all therecurring units (or even, all the recurring units) are recurring units(R1).

Good results were obtained with homopolymers the recurring units (R1) ofwhich were of formula:

RADEL® R polyphenylsulfones from Solvay Advanced Polymers, L.L.C. is anexample of the above homopolymer.

The Poly(Aryl Ether Sulfone) (P2)

More than 50 wt. % of the recurring units are recurring units (R2)containing at least one ether group (—O—), at least one sulfone group(—SO₂—) and at least two arylene groups linked to each other via asecondary, ternary or quaternary carbon atom.

For the sake of clarity, a secondary carbon atom denotes a carbon atombonded to two other carbon atoms with single bonds and to two hydrogenatoms, a ternary carbon atom denotes a carbon atom bonded to three othercarbon atoms with single bonds ant to one hydrogen atom, and aquaternary carbon atom denotes a carbon atom bonded to four other carbonatoms with single bonds.

The two arylene groups linked to each other via a secondary, ternary orquaternary carbon atom are preferably linked to each other via a ternaryor quaternary carbon atom; more preferably, they are linked to eachother via a quaternary atom.

In the recurring units (R2), the secondary, ternary or quaternary carbonatom link advantageously the two arylene groups to each other as schemedbelow:

where A and B may be the same or different. A and B can notably be,independently from each other selected from the group consisting ofhydrogen, hydroxyl, hydroxyalkyls, hydroxyaralkyls, alkoxys,aralkyloxys, amino, aminoalkyls, aminoaralkyls, alkyls (such as methyl,ethyl, butyls), aralkyls (such as benzyl), halogens (in particular,fluorine), halogenated alkyl groups (in particular, trifluoromethyl),halogenoaralkyls, and alkyl and aralkyl groups substituted by carboxylicacid functions, ester functions, amido functions, aldehyde groups and/orketone groups, and mixtures thereof.

A and B are preferably identical to each other. Besides, A and B arepreferably alkyl groups.

More preferably, A is a methyl group and B is also a methyl group.

The recurring units (R2) are preferably selected from the groupconsisting of:

and mixtures thereof.

More preferably, the recurring units (R2) are of the general structuralformula:

Still more preferably, the recurring units (R2) are of the formula:

Optionally, the poly(aryl ether sulfone) (P2) further comprisesrecurring units (R2*) other than recurring units (R2).

Recurring units (R2*) may be selected from the group consisting of:

and mixtures thereof.

Preferably more than 70 wt. % and more preferably more than 90 wt. % ofthe recurring units of the poly(aryl ether sulfone) (P2) are recurringunits (R2). Still more preferably, the poly(aryl ether sulfone) (P2) isa homopolymer of recurring units (R2), essentially all the recurringunits (or even, all the recurring units) are recurring units (R2).

Good results were obtained with homopolymers the recurring units (R2) ofwhich were of the formula:

UDEL® bisphenol A polysulfones from Solvay Advanced Polymers, L.L.C. areexamples of the above homopolymers.

The Per(Halo)Fluoropolymer Material (M34)

As previously mentioned, the polymer composition (C) contains aper(halo)fluoropolymer material (M34).

For the purpose of the invention, a per(halo)fluoropolymer material isintended to denote one or more per(halo)fluoropolymers, i.e. one or morepolyaddition polymers of which at least 98.0 wt. % of the recurringunits are derived from at least one per(halo)fluoromonomer.

For the purpose of the invention, a per(halo)fluoromonomer is intendedto denote any ethylenically unsaturated monomer comprising at least twocarbon atoms and at least one fluorine atom, and which is free ofhydrogen atom directly linked to a carbon atom (i.e. linked to a carbonatom through a single bond C—H).

The per(halo)fluoromonomer may further comprise, in addition to thecarbon and the fluorine atom(s), at least one halogen atom other thanfluorine; thus, the per(halo)fluoromonomer may further comprise at leastone chlorine atom, and/or at least one bromine atom, and/or at least oneiodine atom. Alternatively, the per(halo)fluoromonomer may be free ofhalogen atom other than fluorine; when this condition is met, theper(halo)fluoromonomer is herein called “perfluoromonomer”.

The per(halo)fluoromonomer may also further comprise at least oneheteroatom other than a halogen atom; in particular, it may furthercomprise at least one oxygen atom, phosphorus atom and/or nitrogen atom.

The per(halo)fluoromonomer may also further comprise at least onehydrogen atom linked to a heteroatom; in particular, it may further atleast one hydrogen atom linked to an oxygen atom, a phosphorus atom or anitrogen atom. The case being, the hydrogen atom and the heteroatom formpart of a functional group such as —OH, —NH₂, —C(═O)OH, —C(═O)NH₂,—SO₃H, —SO₂H, —PO₃H₂ or —PO₂H₂. Yet, it is preferred thatper(halo)fluoromonomer be free of any hydrogen atom.

The per(halo)fluoropolymer may be free of recurring units derived fromat least one monomer other than a per(halo)fluoromonomer. Alternatively,the per(halo)fluoropolymer may further comprise up to 2.0 wt. % ofrecurring units derived from at least one ethylenically unsaturatedmonomer other than a per(halo)fluoromonomer.

As examples of ethylenically unsaturated monomers other thanper(halo)fluoromonomers, it can be notably cited:

-   -   ethylene, propylene and C₄-C₁₂ mono-olefins,    -   non fluorinated perhalogenated mono-olefins such as        tetrabromoethylene and hexabromopropylene,    -   partially fluorinated mono-olefins such as vinylidene fluoride        and trifluoroethylene, and    -   partially halogenated, non fluorinated mono-olefins such as        vinylidene chloride.

The per(halo)fluoropolymer may notably be a homopolymer, a random,alternating or block copolymer.

The per(halo)fluoropolymer material (M34) is contained in the polymercomposition (C) in an amount of usually more than 0.1 wt. %, preferablymore than 1.0 wt. %, more preferably more than 2.0 wt. % and still morepreferably more than 3.0 wt. %, based on the total weight of polymercomposition (C). On the other hand, the weight of theper(halo)fluoropolymer material (M34), based on the total weight ofpolymer composition (C), is preferably below 12.0%, more preferablybelow 8.0%; it is still more preferably below 5.5%, or below 5.0%, orbelow 4.5%; the most preferably, it is below 4.0%.

The per(halo)fluoropolymer (P3) is contained in theper(halo)fluoropolymer material (M34) in an amount of from 5 to 95 wt.%, based on the total weight of the per(halo)fluoropolymer material(M34). The weight of the per(halo)fluoropolymer (P3), based on the totalweight of the per(halo)fluoropolymer material (M34) [i.e. the weight ofthe per(halo)fluoropolymer (P3) plus the weight of thepolytetrafluoroethylene (P4)], is preferably of at least 25%, morepreferably of at least 40%, still more preferably of at least 50% andthe most preferably of at least 55%. On the other hand, the weight ofthe per(halo)fluoropolymer (P3), based on the total weight of theper(halo)fluoropolymer material (M34) is preferably of at most 85%, morepreferably of at most 75%, still more preferably of at most 70% and themost preferably of at most 60%.

The Per(Halo)Fluoropolymer(P3)

The per(halo)fluoropolymer (P3) is a per(halo)fluoropolymer (as abovedefined) of which at least 2.0 wt. % of the recurring units arerecurring units (R3) derived from at least one per(halo)fluoromonomer(as above defined) other than tetrafluoroethylene.

Preferably at least 3.0 wt. %, more preferably at least 5.0 wt. % andstill more preferably at least 7.0 wt. % of the recurring units of theper(halo)fluoropolymer (P3) are recurring units (R3).

Essentially all, or even all, the recurring units of theper(halo)fluoropolymer (P3) may be recurring units (R3). However, in anadvantageous manner, the per(halo)fluoropolymer (P3) contains asubstantial weight amount of recurring units other than recurring units(R3). Preferably at most 50 wt. %, more preferably at most 30 wt. %,still more preferably at most 25 wt. %, and the most preferably at most20 wt. % of the recurring units of the per(halo)fluoropolymer (P3) arerecurring units (R3).

The at least one per(halo)fluoromonomer from which the recurring units(R3) are derived is advantageously selected from the group consistingof:

-   -   C₃-C₈ perfluoro-olefins, such as hexafluoropropylene (HFP) and        octafluorobutenes;    -   C₂-C₈ perhalo-olefins containing at least one fluorine atom and        at least one halogen atom other than fluorine (such as chlorine,        bromine or iodine), in particular chlorotrifluoroethylene        (CTFE);    -   perhaloalkylvinylethers containing at least one fluorine atom        complying with general formula CY₂═CYOR_(f1) in which each Y        represents a halogen atom (preferably, a fluorine atom) and        R_(f1) is a C₁-C₆ perhaloalkyl (i.e. a C₁-C₆ alkyl group wherein        each hydrogen atom has been replaced by a halogen atom), such as        —CF₃, —C₂F₅, —C₃F₇, —CBr₃, —CF₂Br, —CF₂Cl or —CF₂I;    -   perhalo-oxyalkylvinylethers containing at least one fluorine        atom complying with general formula CY₂═CYOX₀₁ in which each Y        represents a halogen atom (preferably, a fluorine atom) and X₀₁        is a C₁-C₁₂ perhalo-oxyalkyl group (i.e. a C₁-C₁₂ oxyalkyl group        wherein each hydrogen atom has been replaced by a halogen atom)        including one or more ether groups, such as        perfluoro-2-propoxy-propyl and perbromo-2-propoxy-propyl;    -   functional perhalo-oxyalkylvinylethers containing at least one        fluorine atom complying with general formula CY₂═CYOX₀₂ in which        each Y represents a halogen atom (preferably, a fluorine atom)        and X₀₂ is a C₁-C₁₂ perhalo-oxyalkyl group (preferably, a        perfluoro-oxyalkyl group) including one or more ether groups,        said perhalo-oxyalkyl group being substituted by at least one        functional group, said functional group comprising preferably,        as sole carbon atoms, (i) at least one atom chosen from        hydrogen, sodium, potassium, lithium, rubidium, caesium,        fluorine, chlorine, bromine and iodine, (ii) at least one        heteroatom chosen from oxygen, nitrogen, sulphur and phosphorus,        and, optionally in addition, (iii) at least one carbon atom,        such as —OH, —NH₂, —C(═O)OH, —C(═O)NH₂, —SO₃H, —SO₂H, —PO₃H₂,        —PO₂H₂ and their homologous wherein one or more of the hydrogen        atoms are substituted by a halogen atom or an alkali metal atom        such as —SO₃Na, —SO₃F, —C(═O)ONa and —C(═O)OF;    -   perhalo-methoxy-alkylvinylethers containing at least one        fluorine atom complying with general formula CY₂═CYOCY₂OR_(f2)        in which each Y represents a halogen atom (preferably, a        fluorine atom) and R_(f2) is a C₁-C₆ perhaloalkyl (such as        —CF₂Br) or a C₁-C₁₂ perhalo-oxyalkyl including one or more ether        groups (such as —C₂F₅—O—CF₂Br) and R_(f2) is preferably a C₁-C₆        perfluoroalkyl (such as —CF₃) or a C₁-C₁₂ perfluoro-oxyalkyl        including one or more ether groups (such as —C₂F₅—O—CF₃);    -   perhalodioxoles containing at least one fluorine atom, of        general formula:

-   -   wherein R_(f3A), R_(f4A), R_(f5A), R_(f6A), equal to or        different from each other, are independently selected from the        group consisting of halogen atoms, C₁-C₆ perhaloalkyls (e.g.        —CF₂Br) and C₁-C₆ perhaloalkyls including one or more oxygen        atoms (such as —OCF₂Br or    -   —OCF₂CF₂OCF₂Br); it is understood that, since the        perhalodioxoles of interest contain at least one fluorine atom,        this one must be included in at least one of R_(f3A), R_(f4A),        R_(f5A) and R_(f6A); preferably, R_(f3A), R_(f4A), R_(f5A) and        R_(f6A), equal to or different from each other, are        independently selected from the group consisting of fluorine,        C₁-C₆ perfluoroalkyls (e.g. —CF₃, —C₂F₅, —C₃F₇) and C₁-C₆        perfluoroalkyls including one or more oxygen atoms (such as        —OCF₃ or —OCF₂CF₂OCF₃), and    -   mixtures thereof.

Preferably, the per(halo)fluoromonomer from which the recurring units(R3) are derived is a perfluoromonomer selected from the groupconsisting of:

-   -   —C₃-C₈ perfluoro-olefins, such as hexafluoropropene (HFP);    -   perfluoroalkylvinylethers complying with general formula        CF₂═CFOR_(f7) in which each R_(f7) is a C₁-C₆ perfluoroalkyl        (i.e. a C₁-C₆ alkyl group wherein each hydrogen atom has been        replaced by a fluorine atom), such as —CF₃, —C₂F₅ or —C₃F₇;    -   perfluoro-oxyalkylvinylethers complying with general formula        CF₂═CFOX₀₃ in which X₀₃ is a C₁-C₁₂ perfluoro-oxyalkyl group        (i.e. a C₁-C₁₂ oxyalkyl group wherein each hydrogen atom has        been replaced by a fluorine atom) including one or more ether        groups, such as perfluoro-2-propoxy-propyl; and    -   mixtures thereof.

More preferably, the per(halo)fluoromonomer from which the recurringunits (R3) are derived is a perfluoroalkylvinylether.

Still more preferably, the per(halo)fluoromonomer from which therecurring units (R3) are derived is selected from the group consistingof perfluoromethylvinylether (CF₂═CFOCF₃), perfluoroethylvinylether,perfluoropropylvinylether, and mixtures thereof.

The most preferably, the per(halo)fluoromonomer from which the recurringunits (R3) are derived is perfluoromethylvinylether (CF₂═CFOCF₃).

The per(halo)fluoropolymer (P3) may be free of recurring units derivedfrom tetrafluoroethylene. However, in an advantageous manner, theper(halo)fluoropolymer (P3) contains a substantial weight amount ofrecurring units derived from tetrafluoroethylene; said substantialweight amount may be for example of at least 10 wt. %, at least 20 wt.%, at least 30 wt. % or at least 40 wt. %, based on the total weight ofthe recurring units of the per(halo)fluoropolymer (P3). Preferably atleast 50 wt. %, more preferably at least 70 wt. %, still more preferablyat least 75 wt. %, and the most preferably at least 80 wt. % of therecurring units of the per(halo)fluoropolymer (P3) are derived fromtetrafluoroethylene.

On the other hand, at most 98.0 wt. %, preferably at most 97.0 wt. %,more preferably at most 95.0 wt. %, and still more preferably at most93.0 wt. % of the recurring units of the per(halo)fluoropolymer (P3) arederived from tetrafluoroethylene.

While the per(halo)fluoropolymer (P3) may contain up to 2.0 wt. % ofrecurring units derived from at least one ethylenically unsaturatedmonomer other than a per(halo)fluoromonomer, such recurring units, ifpresent, constitute at most 1.0 wt. % of the recurring units of theper(halo)fluoropolymer (P3), and, very preferably, theper(halo)fluoropolymer is essentially free (or even, completely free) ofrecurring units derived from at least one monomer other than aper(halo)fluoromonomer.

The per(halo)fluoropolymer (P3) may notably be a homopolymer, a random,alternating or block copolymer. The per(halo)fluoropolymer (P3) ispreferably a copolymer, in particular a random copolymer, essentiallyall the recurring units (or even, all the recurring units) are a mixcomposed of from 2.0% to 50 wt. % of recurring units (R3) derived fromat least one per(halo)fluoromonomer other than tetrafluoroethylene andfrom 50% to 98.0% of recurring units derived from tetrafluoroethylene.Good results were obtained when the per(halo)fluoropolymer (P3) was acopolymer, in particular a random copolymer, essentially all therecurring units (or even, all the recurring units) were a mix composedof from 2.0% to 30 wt. % of recurring units (R₃) derived from at leastone perfluoroalkylvinylether of general formula CF₂═CFOR_(f7) withR_(f7) as above defined and at from 70% to 98.0% of recurring unitsderived from tetrafluoroethylene. Excellent results were obtained whenthe per(halo)fluoropolymer (P3) was a copolymer, in particular a randomcopolymer, essentially all the recurring units (or even, all therecurring units) were a mix composed of from 7.0% to 20 wt. % ofrecurring units (R3) derived from perfluoromethylvinylether and at from80% to 93.0% of recurring units derived from tetrafluoroethylene.

The per(halo)fluoropolymer (P3) is advantageously melt-processable. Forthe purpose of the present invention, the term “melt-processable” meansthat the per(halo)fluoropolymer (P3) can be readily processed (i.e.fabricated into shaped articles such as films, fibers, tubes, wirecoatings and the like) by conventional melt extruding, injecting orcasting means. The melt-processability of the per(halo)fluoropolymer(P3) typically requires that its dynamic viscosity, measured at a shearrate of 1 s⁻¹ and at a temperature which exceeds its melting point ofroughly 30° C. [preferably, at a temperature equal to the melting pointof the per(halo)fluoropolymer (P3)+(30±2° C.)], be less than 10⁶ Pa·s;the dynamic viscosity measurement is made with a controlled strainrheometer, employing an actuator to apply a deforming strain to thesample and a separate transducer to measure the resultant stressdeveloped within the sample, and using the parallel plate fixture; themelting point of the per(halo)fluoropolymer (P3) is determined bydifferential scanning calorimetry (DSC), at a heating rate of 10°C./min, in accordance with ASTM D 3418, the whole content of which beingherein incorporated by reference. The per(halo)fluoropolymer (P3) mayhave a dynamic viscosity at a shear rate of 1 s⁻¹ as measured in theabove specified conditions between 10 and 2 000 Pa·s, in particularbetween 10 and 700 Pa·s.

The Polytetrafluoroethylene (P4)

For the purpose of the present invention, a polytetrafluoroethylene isintended to denote any per(halo)fluoropolymer (as above defined) ofwhich more than 98.0 wt. % of the recurring units are derived fromtetrafluoroethylene. Preferably more than 98.5 wt. %, more preferablymore than 99.0 wt. % and still more preferably more than 99.5 wt. % ofthe recurring units of the polytetrafluoroethylene (P4) may be derivedfrom tetrafluoroethylene.

In a certain embodiment, to which the preference may be given,essentially all the recurring units (or even, all the recurring units)of the polytetrafluoroethylene (P4) are derived fromtetrafluoroethylene; the polytetrafluoroethylene (P4) may then bequalified as a “homopolymer”.

In another embodiment, to which the preference may also be given,between 0% and 2 wt. % of the recurring units of thepolytetrafluoroethylene (P4) are derived from one or more ethylenicallyunsaturated monomer(s) other than polytetrafluoroethylene. In said otherembodiment, preferably between 0% and 0.5 wt. % of the recurring unitsof the polytetrafluoroethylene (P4) are derived from one or moreethylenically unsaturated monomer(s) other than polytetrafluoroethylene.Said other ethylenically unsaturated monomer(s) may be any of theper(halo)fluoromonomers other than polytetrafluoroethylene previouslycited in the present document, and/or ethylene, and/or propylene, and/orany C₄-C₁₂ mono-olefin, and/or any non fluorinated, perhalogenatedmono-olefin, and/or any partially fluorinated mono-olefin and/or any nonfluorinated, partially halogenated mono-olefin; said other ethylenicallyunsaturated monomer(s) is (are) preferably any of theper(halo)fluoromonomers other than polytetrafluoroethylene previouslycited in the present document; further, all the preferences expressedhere below concerning the nature of the at least oneper(halo)fluoromonomer from which the recurring units (R3) are derived,apply, mutatis mutandis, to the presently concerned other ethylenicallyunsaturated monomer(s) when these ones are also per(halo)fluoromonomers.

The polytetrafluoroethylene (P4) is advantageously selected from thegroup of the so-known “non fibrillating polytetrafluoroethylenes”, alsocommonly referred to as “low molecular weight polytetrafluoroethylenes”or “low melt viscosity polytetrafluoroethylenes”. The case being, it haspreferably the thermal stability, chemical inertness, lubricity, andhigh melting temperature substantially identical to those of highmolecular weight polytetrafluoroethylenes having typically a numberaverage molecular weight of above 2,000,000.

The polytetrafluoroethylene (P4) has a number average molecular weightof advantageously below 1,000,000, preferably below 700,000, and morepreferably below 500,000. On the other hand, it has a number averagemolecular weight of advantageously above 50,000. The number averagemolecular weight of the polytetrafluoroethylene (P4) is generallycalculated by measuring the total amount N_(g) (expressed in moles/kg)of the polytetrafluoroethylene end groups —CF₂COOH and —CF₂COF,determined by FT-IR spectroscopy. The number average molecular weight(M_(n)) is calculated by means of the following formula M_(n)=2000/N_(g). Gel Permeation Chromatography (GPC) may also be used.

The polytetrafluoroethylene (P4) has advantageously a melt viscosity ofbelow 10⁴ Pa·s, as measured at 372° C. in accordance with the procedureASTM D1239-52T modified as described in U.S. Pat. No. 4,380,618, thewhole content of ASTM D1239-52T and of U.S. Pat. No. 4,380,618 beingherein incorporated by reference.

The polytetrafluoroethylene (P4) may be obtained directly bypolymerization technique such as described in example 1 of U.S. Pat. No.5,223,343, the whole content of which is herein incorporated byreference.

Alternatively, the polytetrafluoroethylene (P4) may be obtained from apowder of a polytetrafluoroethylene having a higher number averagemolecular weight (hereinafter, the “higher molecular weightpolytetrafluoroethylene”), by irradiating said powder with an efficientamount of gamma rays and/or electron beam, so as to decrease the numberaverage molecular weight of the higher molecular weightpolytetrafluoroethylene down to a value below 1,000,000, preferablybelow 700,000, and more preferably below 500,000, thereby obtaining anirradiated powder of the polytetrafluoroethylene (P4) as abovespecified. The higher number average molecular weightpolytetrafluoroethylene has typically a number average molecular weightof above 2,000,000, and it is typically polymerized by an emulsion or asuspension polymerization process. With the emulsion polymerizationprocess, a latex comprising essentially spherical sub-micronic particlesof the higher number average molecular weight polytetrafluoroethylene,emulsified in a dispersion medium (typically, water) is generallyobtained. After coagulation of the sub-micronic particles, a powdercomposed of particles having a volume weighted mean diameter D(4,3) offrom 100 μm to 500 μm micron, as measured by dynamic light scattering(DLS) using a conventional DLS equipment (such as MALVERN Mastersizer2000), is generally obtained. Said powder of the higher number averagemolecular weight polytetrafluoroethylene is then in general irradiatedwith gamma rays, thereby obtaining an irradiated powder of low molecularweight polytetrafluoroethylene. The irradiated powder of the lowmolecular weight polytetrafluoroethylene (P4) is then milled to obtainfinely divided solids as detailed below.

With the suspension polymerization process, a powder composed ofparticles having a volume weighted mean diameter D(4,3) of from 1.0 mmto 10.0 mm, as measured by DLS using a conventional DLS equipment (suchas MALVERN Mastersizer 2000), is generally obtained. Said powders isgeneral irradiated with electron beam, thereby obtaining an irradiatedpowder of low molecular weight polytetrafluoroethylene. The irradiatedpowder of the low molecular weight polytetrafluoroethylene (P4) is thenmilled to obtain finely divided solids as detailed below.

The polytetrafluoroethylene (P4) is advantageously in the form of finelydivided solids, and is then commonly referred to as “PTFE micropowder”.The finely divided solids have a volume weighted mean diameter D(4,3) ofpreferably less than 100 μm, more preferably less than 20 μm, still morepreferably less than 10 μm and the most preferably less than 5 μm, asmeasured by DLS using a conventional DLS equipment (such as MALVERNMastersizer 2000).

The polytetrafluoroethylene (P4) has preferably thermal stability,chemical inertness, lubricity, and high melting temperature similar tohigh molecular weight polytetrafluoroethylenes.

The polytetrafluoroethylene (P4) is advantageously non-melt-processable.For the purpose of the present invention, the term“non-melt-processable” means that the polytetrafluoroethylene (P4)cannot be readily processed (i.e. fabricated into shaped articles suchas films, fibers, tubes, wire coatings and the like) by conventionalmelt extruding, injecting or casting means. The non-melt-processabilityof the polytetrafluoroethylene (P4) is generally related with its quitehigh dynamic viscosity, measured at a shear rate of 1 s⁻¹ and at atemperature which exceeds its melting point of roughly 30° C.[preferably, at a temperature equal to the melting point of thepolytetrafluoroethylene (P4)+(30±2° C.)], with a controlled strainrheometer as above detailed for the per(halo)fluoropolymer (P3): thathigh dynamic viscosity is typically of at least 10⁶ Pa·s. As well knowby the skilled person, polytetrafluoroethylene has generally no easilydiscernible melting point; its notional melting point, measured by DSCat a heating rate of 10° C./min (ASTM D 3418) is generally of about 328°C., and polytetrafluoroethylene starts generally to decompose at about400° C.; even at such a high temperature, polytetrafluoroethyleneremains generally in a rigid gel-like state, which prevents it frombeing readily processed by conventional melt extruding, injecting orcasting means.

ALGOFLON® L 206 and L 203 PTFE and POLYMIST® non fibrillatingpolytetrafluoroethylenes, available from Solvay Solexis, S.p.A., areespecially suitable for use as the polytetrafluoroethylene (P4). Otherespecially suitable non fibrillating polytetrafluoroethylenes arecommercially available notably from DuPont as ZONYL® (e.g. ZONYL®MP1600), and from Daikin Industries, Ltd. as LUBLON® (e.g. LUBLON® L-5).

Optional Ingredient(S)

The polymer composition (C) may be composed essentially of (or even, maybe composed of) the poly(aryl ether sulfone) material (M12) and theper(halo)fluoropolymer material (M34). Alternatively, the polymercomposition (C) may further comprise one or more optional ingredient(s).In rare instances, the weight of the optional ingredient(s), based onthe total weight of the polymer composition (C), may be up to 50%; it ishowever generally below 25%, preferably below 12%, more preferably below8% and still more preferably below 5.5%.

The optional ingredients are advantageously chosen from ingredientswhich do not detrimentally affect the beneficial properties of thepolymer composition (C).

The selection of particular additional ingredients, and the levels, maydepend upon the end use envisioned for the polymer composition (C).

Titanium Dioxide

The polymer composition (C) may be free of titanium dioxide. Yet,preferably, the polymer composition (C) further comprises titaniumdioxide.

Any of the available crystalline forms of titanium dioxide may be used,with the rutile form being preferred due to its superior pigmentproperties.

Titanium dioxide is generally as solid particles, of which the volumeweighted mean diameter D(4,3) is preferably below 5.0 μm, as measured byDLS using a conventional DLS equipment (such as MALVERN Mastersizer2000).

When titanium dioxide is present, its weight, based on the total weightof the polymer composition (C), is preferably above 1.0%, morepreferably above 2.0% and still more preferably above 3.0%; on the otherhand, the weight of titanium dioxide, based on the total weight of thepolymer composition (C), is preferably below 12%, more preferably below8.0%, still more preferably below 5.5% and the most preferably below4.0%.

Zinc Oxide

The polymer composition (C) may be free of zinc oxide. Yet, preferably,the polymer composition (C) further comprises zinc oxide.

When zinc oxide is present, its weight, based on the total weight of thepolymer composition (C), ranges advantageously between 0.01% and 1.00%.The weight of zinc oxide, based on the total weight of the polymercomposition (C), is preferably above 0.10% and more preferably above0.20%; on the other hand, it is preferably below 0.50% and morepreferably below 0.35%.

Optional Polymers

The polymer composition (C) is often free of any polymer other than thepolymers (P 1), (P2), (P3) and (P4). Yet, in a particular embodiment,the polymer composition (C) may further comprise at least one polymerother than the polymers (P1), (P2), (P3) and (P4), in an amount ofgenerally below 25 wt. %, based on the total weight of the polymercomposition (C).

The polymer other than the polymers (P1), (P2), (P3) and (P4) may beselected from the group consisting of: (i) poly(aryl ether sulfone)sother than (P1) and (P2), such as polyetherethersulfones andpolyethersulfones; (ii) perbromofluoropolymers such aspolytetrabromoethylenes of which more than 98.0 wt. % of the recurringunits are derived from tetrabromoethylene; (iii) poly(aryl etherketone)s such as poly(ether ether ketone)s; (iv) poly(ether imide)s; (v)wholly aromatic polyesters; and (vi) mixtures thereof.

Polyetherethersulfones, as herein defined, are polycondensation polymersof which more than 50 wt. % of the recurring units are:

Polyethersulfones, as herein defined, are polycondensation polymers ofwhich more than 50 mol. % of the recurring units are:

said polyethersulfones may optionally further comprise less than 50 mol.% of recurring units

Certain polyethersulfones copolymers are commercially available asRADEL® A from Solvay Advanced Polymers, L.L.C. Polyetherethersulfoneshomopolymers are also commercially available.

Poly(aryl ether ketone)s, as herein defined, are polycondensationpolymers of which more than 50 wt. % of the recurring units contain atleast one ether group (—O—), at least one ketone group (—CO—) and atleast one arylene group.

Poly(ether ether ketone)s, as herein defined, are polycondensationpolymers of which more than 50 wt. % of the recurring units are:

Poly(ether ether ketone)s homopolymers are notably commerciallyavailable as KetaSpire® from Solvay Advanced Polymers, L.L.C.

Wholly aromatic polyesters, as herein defined, are polycondensationpolymers essentially all (or even, all) the recurring units of which arederived from at least one aromatic diacid and at least one aromatic diolin a mole ratio diacid:diol of about 1.00:1.00, and/or at least onearomatic monoacid-monoalcohol. Wholly aromatic polyesters are notablycommercially available as XYDAR® from SOLVAY ADVANCED POLYMERS L.L.C.

Other Optional Ingredients

In certain embodiments of the present invention, the polymer composition(C) further comprises at least one solid filler and/or reinforcingagent, in a weight amount which might be up to 50 wt. %, although beinggenerally below 25 wt. %, based on the total weight of the polymercomposition (C). The polymer composition (C) may include at least 1% orat least 10% of the solid filler and/or reinforcing agent.

Fibers which may serve as reinforcing agent include, but are not limitedto, glass fibers, graphitic carbon fibers, amorphous carbon fibers,synthetic polymeric fibers, aluminum fibers, aluminum silicate fibers,oxide of metals such as aluminum fibers, titanium fibers, magnesiumfibers, wollastonite, rock wool fibers, steel fibers, tungsten fibers,etc. Representative solid fillers include glass, calcium silicate,silica, clays, talc, mica, wollastonite, graphite, aluminum trihydrate,sodium aluminum carbonate, barium ferrite and pigments such as carbonblack, iron oxide, cadmium red, iron blue, and the like.

The polymer composition (C) may also further comprise additionalingredients commonly employed in the resin art such as thermalstabilizers, ultraviolet light stabilizers, flame retardants such aszinc borate, smoke suppressants, plasticizers, and the like.

The polymer composition (C) is advantageously prepared by anyconventional mixing method. A preferred method comprises dry mixing theingredients of polymer composition (C) in powder or granular form, usinge.g. a mechanical blender, then extruding the mixture into strands andchopping the strands into pellets. Accordingly, the individualingredients, commonly provided in the form of chips, pellets or powders,can be physically mixed together in an appropriate apparatus such as amechanical drum tumbler and then optionally dried, if desired,preferably under vacuum or in a circulating air oven, to remove waterfrom the physical mixture so as to facilitate compounding; thecomposition may then be pelletized, for example by melt extrusion toform a strand which, upon solidification, can be broken up into chips orpellets. It is not necessary to combine all ingredients in a singleoperation; for example, a pigment-free composition can be compoundedfirst, and melt blended with the desired amounts of pigment, such asTiO₂, in a later operation.

A closely related aspect of the present invention is directed to apolymer composition (C′) containing

-   -   between 50 and 100 wt. %, based on the total weight of the        polymer composition (C′), of a poly(aryl ether sulfone) material        (M12), composed of        -   from 55 to 100 wt. %, based on the total weight of the            poly(aryl ether sulfone) material (M12), of at least one            poly(biphenyl ether sulfone) (P1), and        -   from 45 to 0 wt. %, based on the total weight of the            poly(aryl ether sulfone) material (M12), of at least one            poly(aryl ether sulfone) (P2) of which more than 50 wt. % of            the recurring units are recurring units (R2) containing at            least one ether group (—O—), at least one sulfone group            (—SO₂—) and at least two arylene groups linked to each other            via a secondary, ternary or quaternary carbon atom, and    -   between 0 and 25 wt. %, based on the total weight of the polymer        composition (C′), of a per(halo)fluoropolymer material (M34′),        composed of        -   from 5 to 95 wt. %, based on the total weight of the            per(halo)fluoropolymer material (M34′), of at least one            melt-processable per(halo)fluoropolymer (P3′), and        -   from 95 to 5 wt. %, based on the total weight of the            per(halo)fluoropolymer material (M34′), of at least one            non-melt-processable per(halo)fluoropolymer (P4′).

The polymer composition (C′), the per(halo)fluoropolymer material(M34′), the per(halo)fluoropolymer (P3′) and the per(halo)fluoropolymer(P4′) comply preferably with any of the above described essential orpreferred features of respectively the polymer composition (C), theper(halo)fluoropolymer material (M34), the per(halo)fluoropolymer (P3)and the polytetrafluoroethylene (P4), including but not limited to thenature and amount of each ingredient of the polymer composition (C),with the exception that in the polymer composition (C′) theper(halo)fluoropolymer (P3′) has to be melt-processable and theper(halo)fluoropolymer (P4′) has to be non-melt-processable.

In particular, in the polymer composition (C′), at least 2.0 wt. % ofthe recurring units of the melt-processable per(halo)fluoropolymer (P3′)are preferably recurring units (R3′) derived from at least oneper(halo)fluoromonomer other than tetrafluoroethylene, and thenon-melt-processable per(halo)fluoropolymer (P4′) is preferably apolytetrafluoroethylene.

Another aspect of the present invention is directed to a shaped articlecomprising the polymer composition (C) or (C′) as above described.

More than 50 wt. % of the invented shaped article may be comprised ofthe polymer composition (C) or (C′). The invented shaped article mayconsist essentially of (or may even consist of) the polymer composition(C) or (C′). The invented article may comprise one or more parts. Morethan 50 wt. % of at least one part the invented shaped article may becomprised of the polymer composition (C) or (C′). The invented shapedarticle may comprise at least one part consisting essentially of (oreven consisting of) the polymer composition (C) or (C′).

The invented shaped article is advantageously used notably anywherewhere high fire resistance, and/or high flowability (low melt viscosityat high shear rate), for thin-wall parts and consequently forlight-weight aircraft interior components), and/or high stiffness and/orhigh toughness (especially as measured by the DYNATUP® test) areimportant.

The invented shaped article can be a three-dimensional article, a fiber,a film, a tape, a sheet (which may be suitable for use in laminating andfor coating applications) or a slab.

The invented shaped article can be fabricated according to the knownmethods in the field, for example, forming the article using injectionmolding or extrusion.

The invented shaped article is preferably an aircraft component, morepreferably an aircraft interior component. Still more preferably, it isselected from the group consisting of overhead passenger service units,window reveals, air return grills, wall panels, overhead storagelockers, serving trays, seat backs, cabin partitions, and ducts.

A last aspect of the present invention concerns an aircraft comprisingat least one aircraft component. The aircraft component may be any ofthe above described aircraft components.

EXAMPLES

The following examples demonstrate the huge and unexpected merits of theinvented polymer compositions.

Used Ingredients

RADEL® R-5100 NT is a natural grade of polyphenylsulfone homopolymer(PPSU), with a melt flow in the range of 14 to 20 g/10 min measured at atemperature of 365° C. and 5.0 kg load.

RADEL® R-5600 NT is also a natural grade of polyphenylsulfonehomopolymer (PPSU), with a heat deflection temperature of 236° C. and amelt flow in the range of 20 to 30 g/10 min at 400° C. and under a 1.2kg load.

Both polyphenylsulfones are commercially available from SOLVAY ADVANCEDPOLYMERS, L.L.C.

UDEL® P-3703 NT is a natural grade of bisphenol A polysulfonehomopolymer (PSU), with a melt flow of about 17 g/10 min measured at343° C. and under a 2.16 kg load, also commercially available fromSOLVAY ADVANCED POLYMERS, L.L.C.

HYFLON® MFA 840 is a tetrafluoroethylene-perfluoromethylvinylethercopolymer with a melt flow rate of about 18.3 g/10 min measuredaccording to ASTM Standard D1238, commercially available for SOLVAYSOLEXIS S.p.A.

POLYMIST® F5A is a micronized, non fibrillating polytetrafluoroethylenehaving a melt flow index of 20 g/10 min measured at 380° C. and under a21 kg load; it is also commercially available for SOLVAY SOLEXIS S.p.A.

KADOX® 911 is zinc oxide available from Zinc Corporation of America.

Kemira OR-470 is rutile titanium dioxide commercially available fromKemira Chemicals.

Examplified Polymer Compositions

8 polymer compositions were prepared, five as comparative examples(named CE1 to CE5) and three in accordance with the present invention(named E1 to E3). The nature and amount of the ingredients of whichthese polymer compositions consist are detailed in table 1 hereinafter,together with the results obtained therewith.

Preparation of the Polymer Compositions

All the polymers to be included in the examplified compositions weredried in a dehumidifying oven at 150° C. overnight for approximately 16hours. The compositions were prepared by tumble blending all theingredients of the polymer compositions for approximately 30 minutes.The polymer compositions were then extruded using a 25 mm twin screwdouble vented Berstorff extruder having an L/D ratio of 33:1 at a rateof approximately 25 lb/hr at a screw speed of 200 rpm. The polymercompositions were extruded at a melt temperature of 350° C. The firstvent port was open to the atmosphere while the second vent port wasconnected to a vacuum pump. The strands were then passed through a watertrough for cooling and then pelletized.

Test Methods

Standard 3.2 mm (0.125 in) thick ASTM test specimens were molded fortensile, flexural and impact properties.

The tensile properties (yield strength, yield elongation, breakelongation and tensile modulus) were measured in accordance with ASTMD-638.

The flexural properties (flexural strength and flexural modulus) weremeasured in accordance with ASTM D-790.

The notched Izod impact was measured in accordance with ASTM D-256.

The penetration impact Dynatup® Dart Drop test was made in accordancewith ASTM D-3763. The maximum load (in lb) and the energy absorbed tomaximum load (in ft-lb) were measured.

OSU Heat Release. A heat calorimetry testing methodology developed atOhio State University, known as the OSU Flammability Test, was used todetermine whether the polymer compositions met U.S. government airworthiness standards. The OSU tests measure the two minute total heatrelease (“2 min THR”) and the peak heat release rate (“Maximum HRR”),expressed in kilowatt times minutes per square meter of surface area(kW-min/m²) and kilowatt per square meter of surface area (kW/m²)respectively, for the first five minutes of a burn test under theconditions of the OSU testing. More precisely, the heat releaseproperties of the polymer compositions were evaluated in accordance withFAR 25. 853 Amendment 25-83, Appendix F, Part IV. Specimens wereprepared by injection molding 6″×6″×0.080″ plaques from the compositionsin a Mitsubishi molding press. The samples were mounted vertically in anenclosed chamber and exposed to flame by multiple pilots mounted at thetop and bottom of the sample fixture. The samples were simultaneouslyexposed to a radiant heat flux of 3.5 W/cm² and 85 ft³/min airflow. Theheat released during combustion was determined by measuring thedifference in temperature of the effluent air from the inlet air.

Rheology. Melt viscosity measurements were made using a Kayeness®capillary rheometer in accordance with ASTM D3835.20 g samples of thepolymer compositions were dried at 160° C. for 2 hours prior to testing.The samples were loaded into the barrel and allowed to melt. A motordriven crosshead with a load transducer used a packing force of 2224 Nto drive a piston through a heated steel cylinder maintained at atemperature of 380° C. The sample was forced through a 1.02 mm (0.040in) diameter, 20.32 mm (0.800 in) long die with an entrance angle of120° at a controlled rate. The rate and force exerted by the sample wereused to calculate the viscosity η_(D) of the polymer composition at eachgiven shear rate (D) tested between 23.2 and 3513 s⁻¹ (η_(23.2), η₁₀₄η_(23.2) η₄₉₈ η₁₅₀₇ and η₃₅₁₃).

Results

All the results are listed in table 1 of next page.

TABLE 1 PPSU Based Formulations PPSU + PSU Based FormulationsFormulations CE1 CE2 E1 CE3 CE4 CE5 E2 E3 RADEL R-5100 NT pbw 94.7594.75 96.25 — — — — — RADEL R-5600 NT pbw — — — 76.25 76.25 76.25 77.4577.45 UDEL P-3703 NT pbw — — — 18.5 18.5 18.5 18.8 18.8 Hyflon MFA 840pbw — 5 2 — 5 5 2 2 Polymist F5A PTFE pbw 5 — 1.5 5 — — 1.5 1.5 Kadox911 Zinc Oxide pbw 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 AllIngredients but Pigment pbw 100 100 100 100 100 100 100 100 Kemira TiO2pbw 4 4 4 4 4 4 4 4 Test Data Units Tensile Properties Yield Strengthpsi 10500 10300 10500 10700 9900 10400 10500 10800 Yield Elongation %7.7 7.7 7.8 7.0 7.1 7.4 7.1 7.1 Break Elongation % 70 74 66 70 51 88 41(17)* Tensile Modulus ksi 313 308 310 332 334 304 330 322 FlexuralProperties Flexural Strength psi 13900 13700 13900 14600 15900 1380014500 15000 Flexural Modulus ksi 356 346 350 358 355 353 362 365 NotchedIzod Impact ft-lb/in 12.5 12.1 13.3 4.5 12.5 12.2 11.2 11.5 Dynatup DartDrop Maximum Load lb 1298 1049 1328 1252 N/A 1036 1295 N/A Energy toMaximum Load ft-lb 32 21 33 33 N/A 20 35 N/A OSU Heat Release 2 min THRkW/m{circumflex over ( )}2-min −2.8 −1.8 −2.7 −0.8 1.2 4.9 1.9 2.5Maximum HRR kW/m{circumflex over ( )}2 36 34 31 33 26 29 34 36 RheologyMeasured values η at Shear Rate D = 23.2 s−1 Pa - s 1388 1203 1286 549609 722 489 557 η at Shear Rate D = 104 s−1 Pa - s 1122 1152 1205 498616 609 493 453 η at Shear Rate D = 498 s−1 Pa - s 534 571 591 299 301372 381 311 η at Shear Rate D = 1507 s−1 Pa - s 325 285 305 210 224 232226 207 η at Shear Rate D = 3513 s−1 Pa - s 208 131 185 143 120 139 152138 N/A means “not available” pbw means “parts by weight” *The presenceof contaminations resulted in an abnormally low value.

Keys to Interpret the Results

These keys, in the form various desirable levels of properties to beachieved, are based on the Applicant's practical high experience and/orthe requirements as set forth by its customers, e.g. manufactures ofaircraft parts. For a polymer composition to be fully satisfactory, eachof its properties should be at a level equal to or higher than theminimum level, as herein defined. Polymer compositions of which one ormore of these properties do not reach the desirable levels havesubstantial chances not to be approved by the end users (as notcompliant to the customers' specs), or even to lamentably fail wheneffectively used in certain practical applications. Certain propertiesare more important than others; precisely, herebelow, a symbol (++, + or−) has been mentioned into brackets to the right of each property toindicate how important this property is: “++” means “very important”,“+” means “important” and “−” means “of low importance”. The nature andamount of each of the ingredients contained in the invented compositionsresult from complex and careful optimization trials made by theApplicant to achieved the most suitable balance of properties. Given therequirements detailed below, the burden appeared very heavy, with veryweak chances of success on the basis of the prior art teachings. Iffinally successful results could be obtained by the Applicant at theintended, this is notably because the invented polymer compositionsexhibited some really unexpected advantageous behaviour, with synergeticeffects being observed.

(Tensile) yield strength (++): the desirable level is typically of atleast 8,000 psi, with values of at least 10,000 psi being preferred.

Yield elongation (+): the desirable level is typically of at least about5%.

Break elongation (−): essentially no minimum desirable level.

Tensile modulus (++): the desirable level is typically of at least 250ksi.

Flexural strength (++): the desirable level is typically of at least12,000 psi, with values of at least 13,500 psi being preferred.

Flexural modulus (++): the desirable level is typically of at least 300ksi.

Notched Izod impact (++): it is highly desirable that the polymercomposition be “supertough”, i.e. that it has a notched Izod impactvalue of at least 10.0 ft-lb/in.

Maximum load and Energy to Maximum Load at Dynatup Dart Drop test (++):it is highly desirable that the polymer composition exhibits a maximumload of at least 1,100 lb and an energy to maximum load of at least 25ft-lb; it is desirable that the polymer composition exhibits a maximumload of at least 1,200 lb and an energy to maximum load of at least 30ft-lb.

2 min THR and Maximum HRR at OSU Heat Release test (++): the most recentairworthiness standards, enacted in 1990, for engineering thermoplasticsrequire that both 2 min THR and maximum HRR have values of 65 or less;moreover, in the future, airworthiness standards are likely to becomestill stricter, leading to a further lowering of permissible THR and/orHRR values; having this in mind, it is desirable that both 2 min THR andmaximum HRR have values of 40 or less.

η at low shear rate (D=23.2 s⁻¹) (−): essentially no maximum desirablelevel.

η at high shear rate (D=3513 s⁻¹) (++): it is highly desirable levelthat η₃₅₁₃ be below 200 Pa·s; for certain particular applications,especially when extremely thin parts have to be molded, the desirablelevel for η₃₅₁₃ is 175 Pa·s or lower.

Interpretation of the Results

PPSU Based Compositions

PTFE-based polymer composition CE1 exhibits a much too high η₃₅₁₃, whichmakes it generally improper for manufacturing thin-walled, andconsequently light-weight, aircraft interior components.

At the Dynatup test, MFA-based polymer composition CE2 exhibits both amuch too low maximum load and a too low energy to maximum load, whichmakes it inappropriate for use in a high number of applicationsrequiring a very high level of toughness. It is to be further noted thatMFA-based polymer compositions CE2 has a tensile strength somewhat lowerthan that of PTFE-based polymer composition CE1 and the PTFE/MFA-basedcomposition E1.

On the other hand, the PTFE/MFA-based composition E1 (according to theinvention) reaches the desirable level for all the properties as abovedetailed: it exhibits a high stiffness, a high toughness, a high fireresistance and a high flowability. Among all the merits of compositionE1, it can be particularly cited its outstanding impact resistance, witha notched Izod impact of 13.3 ft-lb/in, a maximum load at Dynatup testof 1328 lb and an energy to maximum load at the same test of 33 ft-lb,all these properties being surprisingly higher than the same propertiesof both the PTFE-based polymer composition CE1 and the MFA-basedcomposition CE2 (synergistic behaviour).

PPSU+PSU-Based Compositions

PTFE-based polymer composition CE3 exhibits a very bad notched Izodimpact (4.5 ft-lb); for this reason, it is unsuitable for use in a highnumber of applications wherein “supertough” behaviour is mandatory.

MFA-based polymer compositions CE4 and CE5 exhibits both a much too lowmaximum load and a much too low energy to maximum load, which makes italso inappropriate for use in a high number of applications requiring avery high level of toughness. It is to be further noted that MFA-basedpolymer compositions CE4 and CE5 have a tensile strength somewhat lowerthan that of the PTFE-based polymer composition CE3 and thePTFE/MFA-based compositions E2 and E3.

On the other hand, the PTFE/MFA-based compositions E2 and E3 (accordingto the invention) attain the desirable level for all the properties asabove detailed: they exhibit a high stiffness, a high toughness, a highfire resistance and a high flowability. Among all the merits of thecompositions E2 and E3, it can be particularly cited their outstandingimpact resistance in both the notched Izod impact and Dynatup tests,with notched Izod impact values of 11.2-11.5 ft-lb/in (to be comparedwith the poor value measured for CE3), and maximum load values andenergy to maximum load values at Dynatup test of respectively 1171-1295lb and 28-35 ft-lb (to be compared with the poor values measured for CE4and CE5). It can also be cited its extremely low melt viscosity at highshear rate, identical or close to that of the MFA-based compositions CE4and CE5 having the highest fluidity.

All references, patents, applications, tests, standards, documents,publications, brochures, texts, articles, etc. mentioned herein areincorporated herein by reference. Where a numerical limit or range isstated, the endpoints are included. Also, all values and subrangeswithin a numerical limit or range are specifically included as ifexplicitly written out.

Obviously, numerous modifications and variations of the presentinvention are possible in light of the above teachings. It is thereforeto be understood that within the scope of the appended claims, theinvention may be practiced otherwise than as specifically describedherein.

1. (canceled)
 2. A polymer composition (C) comprising: 50 wt. % or moreand below 98 wt. %, based on the total weight of the polymer composition(C), of a poly(aryl ether sulfone) material (M12) which comprises from55 to 100 wt. %, based on the total weight of the poly(aryl ethersulfone) material (M12), of at least one poly(biphenyl ether sulfone)(P1), and from 45 to 0 wt. %, based on the total weight of the poly(arylether sulfone) material (M12), of at least one poly(aryl ether sulfone)(P2) of which more than 50 wt. % of the recurring units are recurringunits (R2) containing at least one ether group (—O—), at least onesulfone group (—SO₂—) and at least two arylene groups linked to eachother via a secondary, ternary or quaternary carbon atom, and 1-25 wt.%, based on the total weight of the polymer composition (C), of aper(halo)fluoropolymer material (M34) which comprises from 5 to 95 wt.%, based on the total weight of the per(halo)fluoropolymer material(M34), of at least one per(halo)fluoropolymer (P3) of which at least 2.0wt. % of the recurring units are recurring units (R3) derived from atleast one per(halo)fluoromonomer other than tetrafluoroethylene, andfrom 95 to 5 wt. %, based on the total weight of theper(halo)fluoropolymer material (M34), of at least onepolytetrafluoroethylene (P4).
 3. The polymer composition according toclaim 2, wherein the weight of the poly(aryl ether sulfone) material(M12), based on the total weight of polymer composition (C), rangesbetween 90% and 98 wt. %.
 4. The polymer composition according to claim2, wherein the poly(aryl ether sulfone) material (M12) consistsessentially of the poly(biphenyl ether sulfone) (P1).
 5. The polymercomposition according to claim 2, wherein the weight of thepoly(biphenyl ether sulfone) (P1), based on the total weight of thepoly(aryl ether sulfone) material (M12), ranges from 65% up to less than95%.
 6. The polymer composition according to claim 2, whereinessentially all the recurring units of the poly(biphenyl ether sulfone)(P1) are recurring units (R1) of formula:


7. The polymer composition according to claim 2, wherein essentially allthe recurring units of the poly(aryl ether sulfone) (P2) are recurringunits (R2) of formula:


8. The polymer composition according to claim 6, wherein essentially allthe recurring units of the poly(aryl ether sulfone) (P2) are recurringunits (R2) of formula:


9. The polymer composition according to claim 2, wherein the weight ofthe per(halo)fluoropolymer material (M34), based on the total weight ofpolymer composition (C), ranges between 2.0 and 5.0 wt. %.
 10. Thepolymer composition according to claim 2, wherein theper(halo)fluoropolymer (P3) is contained in the per(halo)fluoropolymermaterial (M34) in an amount of from 50% to 70 wt. %, based on the totalweight of the per(halo)fluoropolymer material (M34).
 11. The polymercomposition according to claim 2, wherein the per(halo)fluoropolymer(P3) is a copolymer essentially all the recurring units of which are amix composed of from 7.0% to 20 wt. % of recurring units (R3) derivedfrom perfluoromethylvinylether and at from 80% to 93.0% of recurringunits derived from tetrafluoroethylene.
 12. The polymer compositionaccording to claim 2, wherein the polymer composition (C) furthercomprises titanium dioxide.
 13. A shaped article comprising the polymercomposition according to claim
 2. 14. The shaped article according toclaim 13, which is an aircraft interior component.
 15. The shapedarticle according to claim 14, wherein the aircraft interior componentis selected from the group consisting of overhead passenger serviceunits, window reveals, air return grills, wall panels, overhead storagelockers, serving trays, seat backs, cabin partitions, and ducts.
 16. Anaircraft comprising the shaped article according to claim 15.